In an apparatus that displays a document, such as a word processor utilizing a computer, a low-resolution device such as a monitor is utilized as a display device. Certain problems arise as a consequence. For example, the contour of a drawing object in an image is displayed in jagged fashion, or characters become illegible owing to loss of pixels due to downsampling of pixels in order to present a display from source image data. In order to solve these problems, the display is presented in such a manner that the object contour is smoothened as much as possible by smoothing or other processing, or it is so arranged that characters can be read even if pixels are missing.
With these methods, however, smoothing processing takes time and a display cannot be presented instantly in a case where, by way of example, the computer used has insufficient processing capability or the number of drawing objects is very large. Consequently, when a document is manipulated as by scrolling, the operation is not performed in a continuous manner and it may be difficult to carry out certain operations, e.g., it may be difficult to stop the screen at a desired position or to check the content of a document while scrolling it. The end result is a decline in operability and productivity.